What happened to DM Calls?

Me and my boyfriend frequently use the DM vc call systems since we live long distances from each other and have been consistently for the past few years. Have not has to many issues with it until the new updates and layouts came around. Before then, we were able to be on call for practically a whole day and more without it disconnecting itself or have any audio issues. Now we can only be on call for a few hours or less at best and when we are still connected there are times where one of us can hear the other, but the other cannot hear them. It is starting to become very frustrating as we rely alot on vc as a way to communicate and spend time with each other to the point where we're considering finding an alt app just for private calls.